Two ways to turn on the Prev & Next links in Genesis.

prev-next.php

//add_action( 'genesis_after_entry', 'genesis_prev_next_post_nav', 9 );

add_action( 'genesis_before_while', 'genesis_sample_loop_setup' );
/**
 * Setup the loop.
 *
 * @since 1.0.0
 *
 * @return void
 */
function genesis_sample_loop_setup() {

	if ( is_single() ) {
		genesis_prev_next_post_nav();
	}
}